RUBIACEAE. 863 



4 short lobes. Stamens 4, inserted on the throat of the corolla; filaments short; 

 anthers oblong, 2-cuspidate at the base. Ovary 2-celled; ovules solitary in each 

 cavity, pendulous; style filiform, exserted; stigma capitate. Fruit dry, obpyrami- 

 dal, i-2-seeded. Endosperm cartilaginous; cotyledons linear-oblong. [Greek, 

 head-flower.] About 7 species, natives of America and Asia. 



I. Cephalanthus occidentalis L. BUTTON-BUSH. (I. F. f. 3403.) A shrub, 

 or rarely a small tree, glabrous, or somewhat pubescent. Leaves petioled, ovate 

 or oval, entire, acuminate or acute, 7 I 5 cm> l n > 2-6.5 cm. wide; peduncles 

 2-8 cm. long; heads globose, about 2.5 cm. in diameter, the receptacle pubescent; 

 flowers sessile, white, 8-12 mm. long; style about twice the length of the corolla; 

 calyx-tube prolonged beyond the ovary. In swamps and low grounds, N. B. to 

 Ont., Wis., Neb., Fla. and Tex. Also in Cuba. June-Sept. 



4. MITCHELLA L. 



Creeping herbs, with opposite petioled, entire or undulate, evergreen leaves, 

 and white peduncled geminate dimorphous flowers, their ovaries united. Calyx- 

 tube ovoid, the limb 3-6-lobed (usually 4-lobed). Corolla funnelform, usually 

 4-lobed, the lobes recurved, bearded on the inner side. Stamens as many as the 

 lobes of the corolla and inserted on its throat; filaments short and style exserted, 

 or filaments exserted and style short. Ovary 4-celled ; stigmas 4, short, filiform ; 

 ovules i in each cavity, erect, anatropous. Fruit composed of 2 united drupes 

 usually containing 8 roundish nutlets. Seed erect; cotyledons short, obtuse; em- 

 bryo minute. [Named after Dr. John Mitchell, botanist and correspondent of Lin- 

 naeus in Virginia.] Two species, one N. American, the other Japanese. 



i. Mitchella repens L. PARTRIDGE-BERRY. TWIN-BERRY. (I. F. f. 3404.) 

 Stems slender, rooting at the nodes, 1.5-3 dm. long, branching, glabrous, or slightly 

 pubescent. Leaves ovate-orbicular, petioled, obtuse at the apex, rounded or some- 

 what cordate at the base, 6-20 mm. long, dark green, shining; peduncles shorter 

 than the leaves, bearing 2 sessile flowers at the summit; corolla 10-12 mm. long; 

 drupes red (rarely white), broader than high, 4-8 mm. in diameter, persistent 

 through the winter, edible. In woods, N. S. to Fla., Ont., Minn., Ark. and Tex. 

 April-June, sometimes flowering a second time in the autumn. 



6. SPERMACOCE L. 



Herbs, with 4-sided stems, opposite stipulate leaves, and small white flowers, in 

 dense axillary and terminal clusters. Calyx-tube obovoid or obconic, its limb 

 4-toothed. Corolla funnelform, 4-lobed. Stamens 4, inserted on the tube of the 

 corolla. Ovary 2-celled; ovules I in each cavity; style slender; stigma capitate, 

 or slightly 2-lobed. Capsule coriaceous, didymous, of 2 dehiscent carpels, or one 

 dehiscent, the other indehiscent. Seeds oblong, convex on the back; endosperm 

 horny; embryo central; cotyledons foliaceous. [Greek, seed-point, from the sharp 

 calyx- teeth surmounting the carpels.] Two species, natives of America. 



I. Spermacoce glabra Michx. SMOOTH BUTTON-WEED. (I. F. f. 3405.) 

 Glabrous, decumbent or ascending, 2.5-5 dm. long. Leaves lanceolate or elliptic- 

 lanceolate, petioled, or the uppermost sessile, 2-8 cm. long, 8-25 mm. wide, acute 

 at each end, the margins rough; corolla pubescent in the throat, about 3 mm. long, 

 scarcely exceeding the ovate-lanceolate acute calyx-teeth ; stamens and style inclu- 

 ded; capsule obovoid, about 4 mm. long, glabrous; seeds black, punctate. On 

 river-banks and in wet soil, southern Ohio and Ky. to Pla., Kans. and Tex. Also 

 in tropical Am. June-Sept. 



6. DIODIA L. 



Herbs, with opposite, mostly sessile, entire stipulate leaves, and small axillary 

 white lilac or purple flowers. Calyx-tube obconic or obovoid, the limb 2-4-lobed 

 (sometimes i-6-lobed), often with minute teeth between the lobes. Corolla funnel- 

 form or salverform, mostly 4-lobed. Stamens usually 4, inserted on the throat oi 

 the corolla; filaments slender; anthers versatile, oblong-linear, exserted. Ovary 

 2-celled (rarely 3-4-celled); ovules i in each cavity; style filiform, simple, or 2-cleft; 

 stigmas 2. Fruit 2-celled, finally separating into 2 indehiscent carpels. Seed 

 oblong, convex on the back; endosperm horny; cotyledons foliaceous; embryo 



